How to eliminate inefficiency of django query in a loop?

How can the following code be made more efficient (e.g., how to replace the loop with a query)?

def get_question(datetime_now, questions_queryset, user):
    best_schedule = None
    best_question = None
    # HOW TO ELIMINATE THE FOLLOWING LOOP AND REPLACE WITH A QUERY?
    for question in questions_queryset:
        try:
            schedule = (Schedule.objects
                        .filter(question=question, user=user)
                        .latest(field_name='datetime_added')
        except ObjectDoesNotExist:
            schedule = None
        if (schedule and (schedule.date_show_next >= datetime_now) and
                ((not best_schedule) or
                 (schedule.datetime_added >= best_schedule.datetime_added))):
            best_schedule = schedule
            best_question = question

    return best_question

models.py

from django.contrib.auth.models import User
from django.db.models import DateTimeField, ForeignKey, Model, TextField

class Question(Model):
    question = TextField()

class Schedule(Model):
    datetime_added = DateTimeField(auto_now_add=True)
    datetime_show_next = DateTimeField(null=True, default=None)
    question = ForeignKey(Question)
    user = ForeignKey(User, null=True)